When I actually have my guitars...mostly trying to write. The only song I've put any effort into learning recently is Meshuggah - Dancers to a Discordant System, I'm about halfway through it I guess...keeping getting to one particular riff that I can't nail the pattern for. That song is confusing as fuck because the melodic pattern is disassociated from the rhythm, so you play the same riff 3 times and on each repetition each note in the riff is on a different beat & held a different length...then you repeat that whole pattern a number of times etc etc. Its funky.
I guess i also started working on a couple Morbid Angel tracks off Gateways, but didn't really spend more than a day or two with those.